Photometer
Pronunciation : Pho*tom"e*ter
Part of Speech : n.
Etymology : [Photo- + -meter: cf. F. photom?tre.] (Physics)
Definition : Defn: An instrument for measuring the intensity of light, or, more especially, for comparing the relative intensities of different lights, or their relative illuminating power.
Source : Webster's Unabridged Dictionary, 1913